Photo activation dependent unfolding of model proteins to analyse the effect of deamidation on gas-phase structure using top-down ECD FTICR-MS

摘要

Photo activated ECD unfolding maps of deamidated beta-2-microglobulin and Calmodulin show significant differences in ECD fragmentation around the deamidated asparagine residues. This suggests that the alteration from an uncharged to a negative polar group has an effect on the local structure of the protein. In addition there are suggestions from the fragmentation data that the global structure of the protein has also been altered. These findings are supported by top-down HDX-ECD data which shows similar localised unfolding at deamidation sites as well as partial global unfolding.